Hardness tester



Nov. 18, 1969 R. D. BoRGERsl-:N

HARDNESS TESTER 5 Sheets-Sheet 1 Filed March 4, 1966 .IIVIIVIIII lllFIG.

INV'ENTOR ROLAND D. BORGERSEN ATTORNEYS Nov. 18, 1969 R. D. BoRGERsr-:N

HARDNESS TESTER 5 Sheets-Sheet 2 Filed March 4, 1966 ROLAND D.BORG-ERSEN ATTORN EYS Filed March 4, 1966 R. D. BORGERSEN 3 Sheets-Sheet5 BY #M ATTORNEYS United States Patent O U.S. Cl. 73--81 1 ClaimsABSTRACT OF THE DISCLOSURE A hardness tester comprising a ram housing, astationary holding frame supporting the ram housing and supporting ananvil in line with the ram housing, a ram positioned in the housing, aram pressure chamber be`- hind the ram adapted to receive a hydraulicfluid to move the ram forwardly, a iiexible cup-shaped washer positionedin the chamber at the rear of the ram and having an outwardly extendingWall which is expanded against the inner wall of the housing by theforce of the hydraulic uid entering the chamber, thereby providing aseal against fluid leaking between the ram and the inner wall of thehousing, a return spring connected between the ram and the ram housingfor returning the ram to normal position when the fluid is released fromthe chamber, and mechanism for moving the ram housing toward and awayfrom the anvil including threads formed on the outside of the ramhousing, a threaded nut mounted on the ram housing and rotatablysupported by the frame, the ram housing having outside walls positionedclose enough to the frame so as to prevent rotation of the housing whenthe nut is turned, with the frame providing a stop against the movementof the nut in a direction away from the anvil when the ram is beingforced toward the anvil by the uid pressure in the pressure chamber toindent a work piece.

This invention relates to hardness testers, and more particularlyconcerns a hardness tester which is portable and has a test head and apump unit which are separate and which may be supported in a strong,lightweight frame so that all the components of the hardness tester arecompactly arranged.

It is an object of this invention to provide a hardness, tester which isportable and which compactly. contains all the elements for hydraulicoperation and for exerting the necessary high pressure for testing theBrinell hardness of various metals.

It is another object to provide a hardness tester with seals againstleakage of the hydraulic fluid.

It is another object to provide a hardness tester which holds itsaccuracy within prescribed `limits, and maintains the full pressure forany desired length of time.

It is another object of this invention to provide a hardness tester thatmay be readily adapted to work pieces of various sizes and shapes.

It is another object to provide a hardness tester which is simple inconstruction and uses a small number of parts so that the tester may bemanufactured economically, and yet be as accurate as more expensiveinstruments.

It is another object to provide a hardness tester wherein either amechanically operated pump or an electrically operated pump may be usedeconomically.

It is another object of this invention to provide a hardness testerwherein the pressure in the test head may be actuated from a distancewithout diminishing the accuracy of the Brinell test.

Other objects and advantages of this invention, including its simplicityand economy, as well as the ease with which it may be adapted toexisting equipment, will 3,478,568 Patented Nov. 18, 1969 ICC furtherbecome apparent hereinafter and in the drawings, in which:

FIG. 1 is a view in side elevation of a hardness tester constructed inaccordance with this invention;

FIG. 2 is a view in horizontal section taken as indicated -by the linesand arrows 2-2 which appear in FIG. 1;

FIG. 3 is a view in Vertical section taken through the ram housing headas indicated by the lines and arrows 3-3 which appear in FIG. 2, andtaken through the ram housing base as indicated by the lines and arrows3a-3a which appear in FIG. 2; and

FIG. 4 is a view in vertical section of the pump unit.

Although specic terms are used in the following description for clarity,these terms are intended to refer only to the structure shown in thedrawings and are not intended to define or limit the scope of theinvention.

Turning now to the specic embodiment of the invention selected forillustration in the drawings, there is shown a portable hardness testerwhich includes a test head 11 and a pump unit 13 which are supported ina holding frame 15.

Frame 15 includes a pair of side -plates 17 which are made of an alloysteel having a high coeicient of elasticity. Side plates 17 are held inparallel position by Welded steel cross plates 19, 21, 23, and 25, andby base plate 26. Steel cross plate 21 is welded in such a position thatit supports a nut 27 which is connected to housing base 29 of test head11. Plate 21 supports nut 27 rmly but not so tightly as to prevent itsfree rotary motion.

Ram housing base 29 is of square stock and is supported in an uprightposition by side plates 17 and cross plate 21. The four corners or edgesof the square shaped housing base 29 have external threads 31 formedthereon and they receive the internal threads 33 of nut 27. Accordingly,as nut 27 is rotated by hand, ram housing -base 29 is raised or loweredin the vertical direction to provide a simple adjustment as to thedistance between Brinell ball 3S and an anvil 37 which is mounted oncross plate 25 of frame 15 in line with ram housing base 29.

The capacity of the hardness tester for testing specimens or work piecesof Various sizes land shapes is limited only by the strength (andtherefore the optimum desired weight) of the supporting side plates 17,which bear the full thrust of the ram pressure, since when ram 39proceeds forwardly toward anvil 37, the side plates 17 provide a stopagainst rearward movement by nut 27 and the ram housing base 29connected to it.

Larger specimens or work pieces may be worked upon by providing sideplates 17 which have a greater distance Ibetween cross plates 21 and 25.

For ease of manufacture and assembly, the ram housing includes housingbase 29 and housing head 41 which are connected together by a sealedjoint 43 that includes threads 45 and a gasket 47.

Housing base 29 is hollow and includes an inner wall 49, ram 39 having aBrinell ball 35 mounted in its forward end and held there by a retainercap 51, and a ram pressure chamber S3 behind ram 39 and adapted toreceive a hydraulic uid to move the ram forwardly, A ilexible cup-shapedwasher 55 is positioned in chamber 53 at the rear of ram 39 and has anoutwardly extending wall 57 which is expanded against the inner Wal149of housing base 29 by the force of the hydraulic fluid entering chamber53, thereby providing a seal against Huid leaking between ram 39 andinner wall 49 of housing lbase 29.

The forward portion of ram 39 is reduced in cross section and a returnspring 59 is positioned around it and is held in place by a retainingnut 61 screwed into the forward end of housing base 29. Spring 59 exertspressure between nut 61 and shoulder 63 of ram 39 and returns the ram 39to its normal position when the hydraulic fluid is released from chamber53.

Housing head 41 contains a unitary high pressure valve 65, a pressurerelease valve 67, a pressure relief valve 69, and a connection socket 71for a pressure gage 73. High pressure valve 65 is connected to pressurechamber 53 by a duct 75; release valve 67 is connected to chamber 53 byducts 77, 79, and 81; relief valve 69 is connected to chamber 53 byducts 83, 79, and 81; and pressure gage connection socket 71 isconnected to chamber 53 by a duct 85.

A feed hose 87 is connected through a duct to high pressure valve 65,and an exhaust hose 89 is connected through ducts to release valve 67and relief valve 69.

Pump unit 13 is mounted in side plates 17 by screws 90, and includes apump chamber 91, a pump plunger 93, and a pump handle 95 connected topump plunger 93 by a mechanical link 97 and supported by fulcrum 99.

A sump or oil reservoir 101 is formed in pump unit 13 and may containany hydraulic fluid. The open end of sump 101 is threaded to receive aretaining nut 103 which clamps the top of a flexible fluid-proof sac 105against a shoulder 107 formed at the top of sump 101. Elastic sac 105prevents the hydraulic fluid from escaping from sump 101, and expandsand contracts under varying fluid conditions within sump 101, i.e., whenthe fluid is low the sac expands and when the fluid is high the saccontracts. Sac 105 prevents escape of fluid from sump 101 when thetester is operated in other than an upright position.

Sump 101 is connected to a valve chamber 109 by a duct 111, valvechamber 109 is connected to a valve chamber 113 by a horizontal duct 114and a vertical duct 115, and valve chamber 113 is connected to feed hose87.

Sump 101 is also connected to exhaust hose 89 by a duct 1'17.

In operation of the tester, release valve 67 is opened by turning handle119 and the ram 39 and housing base 29 are raised by revolving orrotating the nut 27. The test head 11 is thus raised a sufllcientdistance to admit the test specimen or work piece into the space betweenBrinell ball 35 and anvil 37. Release valve 67 is closed by turninghandle 119, and handle 95 is pumped. When pump plunger 93 is raised,hydraulic fluid is drawn from sump 101 through duct 111 into valvechamber 109 past ball check 121 which is normally held in place by aspring 123. The fluid is sucked into pump chamber 91 through a duct 125.

As plunger 93 is moved downwardly by the cranking of pump handle 95, thefluid trapped in pump cylinder 91 is forced back into valve chamber 109.Since ball check 121 is seated because of the pressure of spring 123 andthe pressure of the fluid from pump cylinder 91, the fluid is forced outof chamber 109 through a horizontal duct 114 and upwardly throughvertical duct 115 into valve chamber 113 past the ball check 129, andthen into flexible feed hose 87.

The fluid in valve chamber 113 cannot reverse its direction of flowbecause of the action of ball check 129 which is seated by spring 131when the fluid pressure from duct 115 diminshes.

As a result of the continued pumping of crank or pump handle 95, thefluid in flexible feed hose 87 flows into high pressure valve 65 and isprevented from reversing its direction of flow from the valve by theaction of its ball check which seats because of spring pressure when thefluid pressure from feed hose 87 diminshes.

As pumping continues, the fluid flows downwardly from high pressurevalve 65 through duct 75 into ram pressure chamber 53. As more fluid isforced into pressure chamber 53 the pressure is gradually built uptherein to move hydraulic ram 39 forwardly.

The ram pressure chamber 53 is connected to pressure gage 73 throughduct 83, so the gage 73 displays the amount of pressure in chamber 53.

Ram pressure chamber 53 is also connected to pressure relief valve 69which may be set for any desired pressure by adjusting the position ofits nut in the chamber so that the force of its spring against its ballcheck becomes greater or less as desired. As shown, the ball is normallyseated by the action of its spring-actuated plunger,` and the tension ofthe spring may be adjusted by rotating the nut which is threaded intothe bore above the spring. When the fluid pressure is too high inchamber 53, theball in relief valve 69 is forced away from its seat, andthe fluid flows through the relief valve chamber into eX- haust hose 89which empties into sump 101.

When continued operation of the pump handle has caused the pressure inchamber 53 to build up to the desired pressure, that pressure will beindicated on gage 73. When the desired pressure is exceeded, the reliefvalve 69 opens and then closes when the pressure decreases to thedesired value. Pumping of the pump handle 95 is then discontinued, andthe desired pressure is held by the system of check valves in theapparatus for the required length of time to complete the test.

Release valve 67 is then opened by turning handle 119, and the pressurein chamber 53 is relieved as the fluid returns through exhaust hose 89to sump 101. The test head is raised by rotating nut 27 so that the testspecimen can be removed. The impression made on the specimen by Brinellball 35 is a standard Brinell test and is read in the usual manner.

After the fluid pressure in chamber 53 has returned to normal, ram 39 isreturned to its normal, at-rest position by return spring 59.

It will be noted that since the test head 11 and pump unit 13 areseparate units, and are connected by flexible hoses, the pump unit 13need not be mounted in frame 15 but may be positioned remotely from thetest head.

Housing base 29 is square in cross section and has its outside wallspositioned close enough to the frame side plates 17 so as to preventrotation of the housing when nut 27 is rotated.

When ram 39 is pushed forwardly by the pressure in chamber 53, the edgesof side plates 17 form a stop against nut 27 since the nut extendsoutwardly past the side plates.

It is to be understood that the form of the invention herewith shown anddescribed is to be taken as a presently preferred embodiment. Variouschanges may be made in the shape, size and arrangement of parts. Forexample, equivalent elements may be substituted for those illustratedand described herein, parts may be reversed, and certain features of theinvention may be utilized independently of the use of other features,all Without departing from the spirit or scope of the invention asdeflned in the subjoined claims.

What is claimed is:

1. A hardness tester comprising a movable cylinder ram housing which ishollow and has an inner wall, a stationary holding frame positionedaround and supporting the ram housing, an anvil mounted on the frame inline with the ram housing, and means for moving the ram housing relativeto the frame toward and away from the anvil to various desired positionsand for holding the ram housing in the desired position.

2. The hardness tester of claim 1 including a ram positioned in thehousing, a ram pressure chamber behind the ram adapted to receive ahydraulic fluid to move the ram forwardly, and a flexible cup-shapedwasher positioned in the chamber at the rear of the ram and having anoutwardly extending wall which is expanded against the inner wall of thehousing by the force of the hydraulic fluid entering the chamber,thereby providing a seal against fluid leaking between the ram and theinner wall of the housing.

3. The hardness tester of claim 1 including a ram positioned in thehousing, a ram pressure chamber behind the ram adapted to receive ahydraulic fluid to move the ram forwardly, and a return springoperatively connected between the ram and the ram housing for returningthe ram to normal position when the uid is released from the chamber.

4. The hardness tester of claim 1 wherein the ram housing includes ahousing base having a ram positioned therein and a ram pressure chamber,a housing head containing high pressure, relief and release valves whichare connected to the ram pressure chamber by duets, and a sealed jointconnecting the housing head and base together.

5. The hardness tester of claim 4 including a flexible feed hoseconnected to the high pressure valve for feeding fluid under highpressure thereto, and a flexible exhaust hose connected to the reliefand release valves for exhausting the fluid from the ram housing.

6. The hardness tester of claim 1 wherein said moving means includesthreads formed on the outside of the ram housing, and a threaded nutmounted on the ram housing and rotatably supported by the frame.

7. The hardness tester of claim 6 wherein the ram housing is square incross section and has outside `walls positioned close enough to theframe so as to prevent rotation of the housing when the nut is turned.

8. The hardness tester of claim 6 wherein the frame includes twospaced-apart side plates connected together by cross plates, and saidnut extends outwardly past the side plates so that the side platesprovide a stop against rearward movement by the nut and the ram housingconnected to it when the ram is being forced forwardly by the fluidpressure in the pressure chamber to indent a work piece.

9. The hardness tester of claim 1 including a pump mounted in theholding frame, and feed and exhaust hoses connected between the pump andthe ram housing.

10. A test head for a hardness tester comprising a ram housing which ishollow and has an inner wall, a ram positioned in the housing, a rampressure chamber behind the ram adapted to receive a hydraulic fluid tomove the ram forwardly, a flexible cup-shaped washer positioned in thechamber at the rear of the ram and having an outwardly extending wallwhich is expanded against the inner wall of the housing by the force ofthe hydraulic fluid entering the chamber, thereby providing a sealagainst fluid leaking between the ram and the inner wall of the housing,a return spring operatively connected between the ram and the ramhousing for returning the ram to normal position when the fluid isreleased from the chamber, threads formed on the outside of the ramhousing, and a threaded nut mounted on the ram housing and adapted to berotatably supported in a frame.

11. The test head according to claim 10 wherein the ram housingvincludes a housing base having the ram and pressure chamber positionedtherein, a housing head containing the high pressure, relief and releasevalves which are connected to the ram pressure chamber by ducts, and asealed joint connecting the housing head and base together.

References Cited UNITED STATES PATENTS 2,203,129 6/1940 Campbell et al.73-83 2,337,573v 12/1943 Schultz 254-93 X 3,370,421 A 2/1968 Piper254-93 X 2,297,778 y 10/ 1942 Knerr et al. 73-81 2,839,917 6/1958Webster 73-81 2,956,432 l0/1960 Henrikson 73-81 3,029,631 4/ 1962Borgersen et al. 73--81 3,247,824 I 4/1966 Rodgers 73-419 3,309,9163/1967 Pearson 73--81 RICHARD C. QUEISSER, Primary Examiner JERRY W.MYRACLE, Assistant Examiner U.S. C1. X.R. 254-93

